Controlling an output of a mining system

ABSTRACT

Controlling an output of a mining system. The control includes receiving, at a processor, a first signal associated with a position of the shearer, determining, using the processor, the position of the shearer based on the first signal, receiving, at the processor, a second signal associated with a load of a conveyor, and determining, using the processor, the load of the conveyor based on the second signal. The method further includes determining, using the processor, an output of the mining system based on the position of the shearer and the load of the conveyor and controlling a speed of the shearer based on the output of the mining system.

BACKGROUND

This invention relates to the control of a longwall mining system. Thelongwall mining system includes a longwall shearer and a conveyor, suchas an armored face conveyor (“AFC”) or a beam stage loader (“BSL”).

SUMMARY

Longwall mining systems for underground mining include, for example, ashearer to remove a mined material (e.g., coal) from a mining face and aconveyor, such as an AFC or BSL, to transport the mined material from anarea where the material is being mined to an area for processing (e.g.,crushing, storage, etc.). The shearer is driven by one or more drivemechanisms (e.g., motors) to change its position along the mining faceand remove the mined material from the mining face. AFCs include, forexample, a first sprocket and a second sprocket around which a chain isprovided. The chain is driven by one or more drive mechanisms (e.g., amaingate motor, a tailgate motor, etc.), and the movement of the chainaround the sprockets causes the conveyor to transport the minedmaterial.

As a shearer moves along the AFC and material is removed from a miningface, it is possible that the AFC is operating in an under-loadedcondition. For example, when there is a relatively small amount of minedmaterial on the AFC (i.e., compared to a maximum load of the AFC), themining system may have available capacity. If, upon identifying that themining system is not operating at full capacity, the performance of themining system is increased, the mining system can take up the availablecapacity and remove more material from the mine. The performance of themine can be increased, for example, by increasing a speed of the shearerand/or a speed of the conveyor. Similarly, if the mining system isoperating at above full capacity, the performance of the mining systemcan be decreased to prevent damage to the mining system.

This invention relates to using a controller to control a speed of ashearer and/or a conveyor of a longwall mining system to regulate theoutput of the mining system. The controller receives signals related toa position of the shearer and/or a load of the conveyor and determinesan output of the mining system. The controller can modify or adjust(i.e., increase or decrease) the speed of the shearer and/or theconveyor based on the output of the mining system in order to improvethe productivity of the mining system. For example, increasing the speedof the shearer causes more mined material to be removed from the miningface, and increasing the speed of the conveyor causes mined material tobe transported to the area for processing more quickly.

In one embodiment, the invention provides a mining system. The miningsystem includes a shearer, a conveyor, a first drive mechanism coupledto the shearer, a first sensor, a second sensor, and a controller. Thefirst drive mechanism is operable to drive the shearer. The first sensoris operable to generate a first signal related to a position of theshearer. The second sensor is operable to generate a second signalrelated to a load of the conveyor. The controller is operable to receivethe first signal from the first sensor, determine the position of theshearer based on the first signal, receive the second signal from thesecond sensor, and determine the load of the conveyor based on thesecond signal. The controller is further operable to determine an outputof the mining system based on the position of the shearer and the loadof the conveyor and control a speed of the shearer based on based on theoutput of the mining system.

In another embodiment, the invention provides a method of controlling anoutput of a mining system. The method includes receiving, at aprocessor, a first signal associated with a position of the shearer,determining, using the processor, the position of the shearer based onthe first signal, receiving, at the processor, a second signalassociated with a load of a conveyor, and determining, using theprocessor, the load of the conveyor based on the second signal. Themethod further includes determining, using the processor, an output ofthe mining system based on the position of the shearer and the load ofthe conveyor and controlling a speed of the shearer based on the outputof the mining system.

In another embodiment, the invention provides a mining system. Themining system includes a shearer, a conveyor, a first drive mechanismcoupled to the conveyor, a first sensor, a second sensor, and acontroller. The first drive mechanism is operable to drive the conveyor.The first sensor is operable to generate a first signal related to aposition of the shearer. The second sensor is operable to generate asecond signal related to a load of the conveyor. The controller isoperable to receive the first signal from the first sensor, determinethe position of the shearer based on the first signal, receive thesecond signal from the second sensor, and determine the load of theconveyor based on the second signal. The controller is further operableto determine an output of the mining system based on the position of theshearer and the load of the conveyor and control a speed of the conveyorbased on the output of the mining system.

In another embodiment, the invention provides a method of controlling anoutput of a mining system. The method includes receiving, at aprocessor, a first signal associated with a position of a shearer,determining, using the processor, the position of the shearer based onthe first signal, receiving, at the processor, a second signalassociated with a load of the conveyor, and determining, using theprocessor, the load of the conveyor based on the second signal. Themethod further includes determining, using the processor, an output ofthe mining system based on the position of the shearer and the load ofthe conveyor and controlling a speed of the conveyor based on the outputof the mining system.

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of the configuration and arrangement of components set forthin the following description or illustrated in the accompanyingdrawings. The invention is capable of other embodiments and of beingpracticed or of being carried out in various ways. Also, it is to beunderstood that the phraseology and terminology used herein are for thepurpose of description and should not be regarded as limiting. The useof “including,” “comprising,” or “having” and variations thereof hereinare meant to encompass the items listed thereafter and equivalentsthereof as well as additional items. Unless specified or limitedotherwise, the terms “mounted,” “connected,” “supported,” and “coupled”and variations thereof are used broadly and encompass both direct andindirect mountings, connections, supports, and couplings.

In addition, it should be understood that embodiments of the inventionmay include hardware, software, and electronic components or modulesthat, for purposes of discussion, may be illustrated and described as ifthe majority of the components were implemented solely in hardware.However, one of ordinary skill in the art, and based on a reading ofthis detailed description, would recognize that, in at least oneembodiment, the electronic based aspects of the invention may beimplemented in software (e.g., stored on non-transitorycomputer-readable medium) executable by one or more processing units,such as a microprocessor and/or application specific integrated circuits(“ASICs”). As such, it should be noted that a plurality of hardware andsoftware based devices, as well as a plurality of different structuralcomponents may be utilized to implement the invention. For example,“servers” and “computing devices” described in the specification caninclude one or more processing units, one or more computer-readablemedium modules, one or more input/output interfaces, and variousconnections (e.g., a system bus) connecting the components.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a longwall mining system.

FIG. 2 is a perspective view of a longwall shearer associated with themining system of FIG. 1.

FIG. 3 is a perspective view of a portion of a conveyor associated withthe mining system of FIG. 1.

FIG. 4 illustrates a controller for the mining system of FIG. 1according to an embodiment of the invention.

FIG. 5 is a diagram illustrating a relationship between a position ofthe shearer of FIG. 2 and an amount of mined material loaded on theconveyor of FIG. 3.

FIG. 6 is a diagram illustrating a manner in which chain tension variesalong the length of the conveyor of FIG. 3.

FIG. 7 is a process for optimizing the mining system of FIG. 1

FIG. 8 is another process for optimizing the mining system of FIG. 1.

FIG. 9 is another process for optimizing the mining system of FIG. 1.

DETAILED DESCRIPTION

The invention described herein relates to the control of a longwallmining system. The longwall mining system includes, for example,longwall shearers, a conveyor, such as an armored face conveyor (“AFC”)or beam stage loaders (“BSL”), and a controller. The controller isoperable to receive one or more signals related to a characteristic ofthe longwall mining system (e.g., a position of the shearer, a load ofthe conveyor, etc.) and determine an output of the mining system basedon the characteristics. The controller is further operable to controlthe speed of the shearer and/or the speed of the conveyor based on theoutput of the mining system. The speed of the shearer and/or theconveyor can be adjusted or modified to increase the productivity of themining system without overloading the conveyor or over taxing theshearer. For descriptive purposes, the invention is described hereingenerally with respect to conveyors.

FIG. 1 illustrates a longwall mining system 100. The mining system 100includes a discharge conveyor 105 extending away from a mining face 110.Two conveyors 115 and 120 extend along the mining face 110. Longwallshearers 125 are mounted on the conveyors 115 and 120 for movement in alateral direction substantially parallel to the mining face 110. Theconveyors 115 and 120 include a drive end defining a discharge portion130 positioned adjacent the discharge conveyor 105. The dischargeconveyor 105 includes a crusher 135 for reducing the size of the minedmaterial for further processing and storage. Conveyor translationdevices 140 are operable to move the conveyors 115 and 120 toward themining face 110. In some embodiments, the longwall mining system 100 isused in an underground mining operation and further includes a pluralityof powered roof supports (not shown).

As illustrated in FIG. 2, each longwall shearer 125 includes a generallyrectangular chassis 200 and a pair of articulating arms 205, each ofwhich supports a cutter assembly 210. The arms 205 are pivotally coupledto opposite ends of the chassis 200 and are pivoted by actuators 215coupled between the arms 205 and the chassis 200. Each arm 205 supportsa cutter motor 220 operable to rotatably drive cutter assembly 210. Thecutter assembly 210 is generally cylindrical and includes a firstcutting surface 225 for removing material from the mining face 110 whenthe longwall shearer 125 moves substantially parallel to the mining face110, and a second cutting surface 230 defined by an end surface of thecutter assembly 210 for removing material from the mining face 110 whenthe longwall shearer 125 moves substantially normal to the mining face110. The first cutting surface 225 may generally be cylindrical, and thesecond cutting surface 230 may be generally circular, annular, conical,or frusto-conical depending, among other things, on the type of materialthe cutting surfaces 225, 230 are intended to cut. Both the first andsecond cutting surfaces 225, 230 can be provided with a plurality ofcutting teeth 235 of varying configurations for removing material fromthe mining face 110. In the illustrated embodiment, the teeth 235 aremounted on both the first and second cutting surfaces 225, 230.

The longwall shearer 125 also includes a pair of inboard support feet240 and a pair of outboard support feet 245 (only one of the outboardsupport feet is visible in FIG. 2). The inboard and outboard supportfeet 240, 245 are configured or operable for mounting to the conveyors115, 120 such that the longwall shearer 125 can move laterally along theconveyors 115, 120 from the discharge portion 130 to the return end ofthe conveyors 115, 120 and back again. The longwall shearer 125 isdriven by a drive mechanism (e.g., a variable speed motor) along theconveyors 115, 120.

FIG. 3 illustrates a portion of a longwall conveyor 300 similar to theconveyors 115, 120 of FIG. 1. The conveyor 300 includes a return end305, a conveying element or chain 310 that travels between the returnend 305 and the discharge portion 130 (see FIG. 1), and a sensorassembly 315 proximate to the return end 305. The chain 310 is driven bya drive mechanism, such as a variable speed motor, associated with thedischarge portion 130. The return end 305 includes a frame 320, asprocket or take-up shaft 325 mounted on the frame 320, and at least onehydraulic cylinder (not shown). The frame 320 moves with respect to thedischarge portion 130 based on the extension and retraction of thehydraulic cylinder. The chain 310 passes around the take-up shaft 325 totravel in a continuous loop between the discharge portion 130 and thereturn end 305. The chain 310 includes a plurality of flight members 330mounted on the chain 310 and spaced apart by a first distance in adirection of travel 335 of the chain 310.

FIG. 4 illustrates a controller 400 associated with the mining system100. The controller 400 is connected or coupled to a variety ofadditional modules or components, such as a user interface module 405,one or more indicators 410, a power supply module 415, one or moresensors 420, a shearer parameters module 425, a conveyor parametersmodule 430, a data store or database 435, a first drive mechanism anddrive 440 (e.g., associated with one or more shearers 125), and a seconddrive mechanism and drive 445 (e.g., associated with one or moreconveyors 300). In some embodiments, the first drive mechanism and drive440 includes a first motor and a first motor drive, and the second drivemechanism and drive 445 includes a second motor and second motor drive.In some embodiments, a first motor and first motor drive 440 and thesecond motor and second motor drive 445 each include switchgearassemblies. Embodiments of the invention described herein are describedwith respect to the drive mechanisms and drives being motors and motordrives.

The one or more sensors 420 are, for example, sensors configured oroperable to measure or sense a characteristic of the shearer 125 (e.g.,a shearer position, a shearer speed, etc.), sensors configured oroperable to measure or sense a characteristic of the conveyor 300 (e.g.,a chain position, a chain speed, a chain tension, etc.), powertransducers within the longwall mining system 100 configured or operableto measure or sense an electrical characteristic (e.g., current,voltage, power factor, torque, speed, input power, output power, etc.),load cells or sensors (e.g., tension sensors, load pins, etc.) operableto generate a signal related to a load of the conveyor, etc. In someembodiments, the conveyor includes a plurality of load sensor assembliesat different locations on the conveyor for generating a plurality ofsignals related to the load of the conveyor. The load of the conveyorcan then be determined based on a sum or average of the measurementsfrom the load sensor assemblies. In some embodiments, the sensorassemblies are similar to those disclosed in U.S. Pat. No. 8,931,628,entitled “AUTOMATED FACE CONVEYOR CHAIN TENSION LOAD SENSOR IN CHAINTENSION PLATE,” the entire content of which is hereby incorporated byreference. In other embodiments, the sensor assemblies are similar tothose disclosed in U.S. Pat. No. 8,636,140, entitled “CHAIN TENSIONSENSOR,” the entire content of which is also hereby incorporated byreference.

The controller 400 includes combinations of hardware and software thatare operable to, among other things, determine an output of the miningsystem 100, control the operation of the mining system 100, activate theone or more indicators 410 (e.g., a liquid crystal display [“LCD”]),monitor the operation of the mining system 100, etc. In someembodiments, the controller 400 includes a plurality of electrical andelectronic components that provide power, operational control, andprotection to the components and modules within the controller 400and/or the mining system 100. For example, the controller 400 includes,among other things, a processing unit 450 (e.g., a microprocessor, amicrocontroller, or another suitable programmable device), a memory 455,input units 460, and output units 465. The processing unit 450 includes,among other things, a control unit 470, an arithmetic logic unit (“ALU”)475, and a plurality of registers 480 (shown as a group of registers inFIG. 4), and is implemented using a known computer architecture, such asa modified Harvard architecture, a von Neumann architecture, etc. Theprocessing unit 450, the memory 455, the input units 460, and the outputunits 465, as well as the various modules connected to the controller400 are connected by one or more control and/or data buses (e.g., commonbus 485). The control and/or data buses are shown generally in FIG. 4for illustrative purposes. The use of one or more control and/or databuses for the interconnection between and communication among thevarious modules and components would be known to a person skilled in theart in view of the invention described herein. In some embodiments, thecontroller 400 is implemented partially or entirely on a semiconductorchip, is a field-programmable gate array (“FPGA”), is an applicationspecific integrated circuit (“ASIC”), etc.

The memory 455 includes, for example, a program storage area and a datastorage area. The program storage area and the data storage area caninclude combinations of different types of memory, such as read-onlymemory (“ROM”), random access memory (“RAM”) (e.g., dynamic RAM[“DRAM”], synchronous DRAM [“SDRAM”], etc.), electrically erasableprogrammable read-only memory (“EEPROM”), flash memory, a hard disk, anSD card, or other suitable magnetic, optical, physical, or electronicmemory devices or data structures. The processing unit 450 is connectedto the memory 455 and executes software instructions that are capable ofbeing stored in a RAM of the memory 455 (e.g., during execution), a ROMof the memory 455 (e.g., on a generally permanent basis), or anothernon-transitory computer readable medium such as another memory or adisc. Software included in the implementation of the mining system 100can be stored in the memory 455 of the controller 400. The softwareincludes, for example, firmware, one or more applications, program data,filters, rules, one or more program modules, and other executableinstructions. The controller 400 is configured or operable to retrievefrom memory and execute, among other things, instructions related to thecontrol processes and methods described herein. In other constructions,the controller 400 includes additional, fewer, or different components.

The shearer parameters module 425 is connected to or associated with oneor more shearers 125 that are driven by the first drive mechanism anddrive 440. The shearer parameters module 425 is configured or operableto receive signals associated with one or more parameters (e.g., shearerposition, shearer speed, motor speed, motor current, motor voltage,input power, etc.) of the one or more shearers 125. In some embodiments,the shearer parameters module 425 generates signals related to theshearer parameters. In other embodiments, the shearer parameters module425 includes or is connected to the one or more sensors 420 and receivessignals from the one or more sensors 420 related to the shearerparameters.

The conveyor parameters module 430 is connected to or associated withone or more conveyors 300 that are driven by the second drive mechanismand drive 445. The conveyor parameters module 430 is configured oroperable to receive signals associated with one or more parameters ofthe conveyor (e.g., conveyor load or loading, conveyor speed, motorspeed, motor current, motor voltage, input power, etc.). In someembodiments, the conveyor parameters module 430 generates signalsrelated to the conveyor parameters. In other embodiments, the conveyorparameters module 430 includes or is connected to the one or moresensors 420 and receives signals from the one or more sensors 420related to the conveyor parameters.

The motors 440, 445 are controlled by control signals received from thecontroller 400 or another associated controller. The motors 440, 445 arealso coupled to gear reduction boxes to reduce the rotational speed ofthe motors 440, 445 to a rotational speed appropriate for the shearer125 and the conveyor. In some implementations, the controller 400 isconfigured or operable to control the motors 440, 445 and the miningsystem 100 autonomously using the sensors 420 and one or more storedprograms or modules. In other implementations, the controller 400 isconfigured or operable to control the motors 440, 445 and the miningsystem 100 based on a combination of manual inputs and automaticcontrols.

The user interface module 405 is used to control or monitor the shearer125, the conveyor 300, and/or the mining system 100. For example, theuser interface module 405 is operably coupled to the controller 400 tocontrol the speed of the shearer 125, the speed of the conveyor 300, thespeed of the motors 440, 445, etc. The user interface module 405 caninclude a combination of digital and analog input or output devicesrequired to achieve a desired level of control and monitoring for themining system 100. For example, the user interface module 405 caninclude a display and input devices such as a touch-screen display, oneor more knobs, dials, switches, buttons, etc. The display is, forexample, a liquid crystal display (“LCD”), a light-emitting diode(“LED”) display, an organic LED (“OLED”) display, an electroluminescentdisplay (“ELD”), a surface-conduction electron-emitter display (“SED”),a field emission display (“FED”), a thin-film transistor (“TFT”) LCD,etc. In other constructions, the display is a Super active-matrix OLED(“AMOLED”) display. The user interface module 405 can also be configuredor operable to display conditions or data associated with the miningsystem 100 in real-time or substantially real-time. For example, theuser interface module 405 is configured or operable to display measuredcharacteristics of the mining system 100 (e.g., of the shearer 125, theconveyor 300, etc.), the status of the mining system 100, faultconditions (e.g., slack chain, zero tension chain, etc.), an amount ofmined material on the conveyor 300, etc. In some implementations, theuser interface module 405 is controlled in conjunction with the one ormore indicators 410 (e.g., LEDs) to provide visual indications of thestatus or conditions of the mining system 100.

Although a single controller is illustrated in FIG. 4, in otherconstructions, the controller 400 may be separated into a plurality ofcontrollers. For example, the controller 400 may be separated into aconsolidated control unit (“CCU”), a programmable control unit (“PCU”),etc. The CCU can be housed in an explosion-proof enclosure and providescontrol over the conveyor system. The PCU is an intrinsically safesystem that can be interfaced with the CCU for, among other things,stopping, inhibiting, tripping, etc., the operation of the conveyor.

As previously indicated, in some embodiments, the controller 400 isconfigured or operable to control the speed of the one or more shearers125 based on whether the mining system 100 is being fully (e.g., closeto 100%) utilized. The controller 400 is also configured or operable toreceive signals from the one or more sensors 420 associated with themotors 440, 445, the shearer 125, the conveyor 300, or other componentsof the mining system 100. The signals from the sensors 420 are relatedto, for example, a position of the shearer 125, a load of the conveyor300, etc. The controller 400 then processes and analyzes the signals todetermine an output of the mining system 100. The output of the miningsystem is a measure of the productivity of the longwall mining system10, and may be measured in units of tons (i.e., of mined material) perunit time (e.g., minutes, hours, etc.). The output of the mining systemis dependent upon, among other things, an amount of mined materialremoved from the mining face 110 by the shearers 125, the amount ofmined material loaded on the conveyor 300, and a speed of the shearer125. In some embodiments, the controller 400 determines whether theoutput of the mining system 100 is optimized by comparing the output ofthe mining system to a predetermined threshold, such as a maximum outputpossible for the mining system 100. The predetermined threshold is, forexample, between 90% and 100% of the maximum (safe) output of the miningsystem 100 (e.g., an output that will not overload the conveyor 300 orover tax the shearers 125). The controller 400 then controls the speedof the shearer 125 based on the comparison of the output to thethreshold. In some embodiments, the controller 400 controls the speed ofthe shearer 125 based on a function related to the output of the miningsystem 100. In other embodiments, the controller 400 controls the speedof the shearer 125 based on a value in a look-up table related to theoutput of the mining system 100. The speed of the shearer can be a speedat which the shearer is moved along the conveyor 300 and/or a speed atwhich the cutter assemblies 210 are rotated.

Additionally or alternatively, the controller 400 is configured oroperable to control the speed of the one or more conveyors 300 based onwhether the mining system 100 is being fully (e.g., close to 100%)utilized. The controller 400 is also configured or operable to receivesignals from the one or more sensors 420 associated with the motors 440,445, the shearer 125, the conveyor 300, or other components of themining system 100. The signals from the sensors 420 are related to, forexample, a position of the shearer 125, a load of the conveyor 300, etc.The controller 400 then processes and analyzes the signals to determinean output of the mining system 100. The output of the mining system 100is a measure of the productivity of the mining system 100, and may bemeasured in units of tons (i.e., of mined material) per unit time (e.g.,minutes, hours, etc.). The output of the mining system is dependentupon, among other things, an amount of mined material removed from themining face 110 by the shearer 125, the amount of mined material loadedon the conveyor 300, and the speed of the shearer 125. In someembodiments, the controller 400 determines whether the output of themining system 100 is optimized by comparing the output of the miningsystem to a predetermined threshold, such as a maximum output possiblefor the mining system 100. The predetermined threshold is, for example,between 90% and 100% of the maximum (safe) output of the mining system100 (e.g., an output that will not overload the conveyor 300 or over taxthe shearers 125). The controller 400 then controls the speed of theconveyor 300 based on the comparison of the output to the threshold. Insome embodiments, the controller 400 controls the speed of the conveyor300 based on a function related to the output of the mining system 100.In other embodiments, the controller 400 controls the speed of theconveyor 300 based on a value in a look-up table related to the outputof the mining system 100.

The output of the mining system 100 is a measure of the productivity ofthe mining system 100. During operation, the output of the mining system100 is preferably as close to the maximum output possible for the miningsystem 100 based on the mined material, mining conditions, systemconfiguration, etc. The output of the mining system 100 at any giventime can be expressed as a percentage (%) of a maximum output of themining system 100. As such, the longwall mining system is mostproductive and the most utilized when the output of the mining system100 is approximately 100% of the maximum output (e.g., between 90% and100%). If the output of the mining system is less than the maximumoutput, the controller 400 adjusts (e.g., increases) the speed of theshearer 125 and/or the conveyor 300 to increase the output of the miningsystem 100.

The output of the mining system 100 is determined based on the positionof the shearer 125 and/or the load (e.g., of mined material, powerconsumption, etc.) on the conveyor 300. FIGS. 5 and 6 illustrate therelationship between the position of the shearer 125 and an amount ofmined material on the conveyor 300, and the tension in the conveyorchain 310 (which is related to the load of the conveyor, powerconsumption of the conveyor, etc.). Specifically, FIG. 5 is a diagram600 that illustrates a relationship between the position of the shearer125 and the amount of mined material loaded on a conveyor 300 (i.e., intons per meter [“t/m”]), and is illustrated with time (i.e., minutes)along an x-axis of a coordinate system. The position of the shearer 125is depicted with respect to a percentage (%) of the mining face 110(i.e., between a maingate and a tailgate of the mining face 110). Forexample, if the shearer 125 is located at an extreme far end of a miningsystem 100 (e.g., tailgate), the percentage of the shearer's position is100% (i.e., with respect to the full range of motion of the shearer 125along the mining face 110). As the position of the shearer 125approaches the 100% position, the amount of mined material that isloaded on the conveyor 300 also increases in relation to the position ofthe shearer 125. Therefore, the output of the mining system 100 isrelated to the position of the shearer 125 along the mining face 110,and the position of the shearer can be used to determine and/or predictthe output of the mining system 100.

Similarly, FIG. 6 is a diagram 700 of the tensions (i.e., in tons) atvarious locations of the chain 310 with respect to time. For example,the diagram 700 includes the top maingate tension, the top tailgatetension, the bottom maingate tension, and the bottom tailgate tension.The tensions are given in tons and are also related to the position ofthe shearer 125 and the loading of the conveyor 300 (e.g., the amount ofmined material loaded on the conveyor 300). With comparison to FIG. 5,as the amount of mined material loaded on the conveyor 300 increases,the tension in the chain 310 increases. Similarly, as the position ofthe shearer 125 increases, the tension in the chain 310 increases. Insome embodiments, the aggregate tension in the chain 310, the averagetension in the chain 310, and/or the tension in the chain 310 at aspecific location is used to determine or calculate the load of theconveyor 300. In other embodiments, the aggregate tension in the chain310, the average tension in the chain 310, and/or the tension in thechain 310 at a specific location is considered to be representative ofthe load of the conveyor 300. The load of the conveyor 300 and/or theposition of the shearer 125 can, therefore, be used to determine theoutput of the mining system 100.

The process 800, 900, and 1000 are associated with and described hereinwith respect to determining the output of the mining system 100 andcontrolling the speed of the shearer 125 and/or the conveyor 300 basedon the output of the mining system. Various steps described herein withrespect to the processes 800, 900, and 1000 are capable of beingexecuted simultaneously, in parallel, or in an order that differs fromthe illustrated serial manner of execution. The processes 800, 900, and1000 may also be capable of being executed using fewer steps than areshown in the illustrated embodiment. Additionally, the controller 400 isoperable to execute the process 800, 900, and 1000 at the same time orin tandem with other processes.

FIG. 7 illustrates a process 800 for controlling the mining system 100.At step 805, the controller 400 receives a first signal related to aposition of the shearer 125. The controller 400 is configured oroperable to determine or calculate a value for the position of theshearer 125, for example, as a percentage (%) of position along themining face 110 (step 810). At step 815, the controller 400 receives asecond signal related to a load of the conveyor 300. The controller 400is configured or operable to determine or calculate a value for the loadof the conveyor 300, for example, in units of tons per meter (step 820).

At step 825, the controller 400 determines or calculates an output ofthe mining system 100 based on the characteristics determined in step810 (i.e., the position of the shearer 125) and step 820 (i.e., the loadof the conveyor 300). The output of the mining system 100 can becalculated, for example, by determining how many tons of mined materialthe shearer 125 removes during a lateral movement along the mining face110, how many tons of mined material the conveyor 300 is moving towardsthe discharge portion 130 in a unit time (e.g., minutes, hours, etc.),etc. At step 830, the controller 400 analyzes the output of the miningsystem 100. In one embodiment, the controller 400 is configured oroperable to compare the output of the mining system to a predeterminedthreshold. The predetermined threshold is, for example, the maximumoutput of the mining system 100. As described above, the output of themining system 100 can be described as a percentage (%) of the maximumoutput of the mining system 100. Additionally or alternatively, thecontroller 400 can analyze the output of the mining system 100 using afunction and/or look-up table related to the output of the mining system100 (e.g., the present output of the mining system is an input to afunction or a look-up table and the function or look-up table producesnecessary control signals or parameters). Based on the analysis of theoutput of the mining system 100, the controller 400 is configured oroperable to control the speed of the shearer 125 (step 835) and thespeed of the conveyor 300 (step 840). For example, the controller 400can increase the speed of the motor 440 driving the shearer 125 in orderto increase the amount of mined material removed from the mining face110. The controller 400 can also increase the speed of the motor 445driving the conveyor 300 in order to increase the speed of the conveyor300 and the amount of mined material that is conveyed from the miningface 110. The process 800 can be performed continuously during theoperation of the mining system 100 to constantly adjust or modify thespeed of the shearer 125 and the conveyor 300 in order to maximize theproductivity of the mining system 100. In some embodiments, the outputof the mining system 100 is not determined and the position of theshearer 125 and the load of the conveyor 300 are used to directlycontrol the speed of the shearer 125 and the conveyor 300.

FIG. 8 illustrates a process 900 for controlling the mining system 100.At step 905, the controller 400 receives a first signal related to aposition of the shearer 125. The controller 400 is configured oroperable to determine or calculate a value for the position of theshearer 125, for example, as a percentage (%) of position along themining face 110 (step 910). At step 915, the controller 400 receives asecond signal related to a load of the conveyor 300. The controller 400is configured or operable to determine or calculate a value for the loadof the conveyor 300, for example, in units of tons per meter (step 920).

At step 925, the controller 400 determines or calculates an output ofthe mining system 100 based on the characteristics determined in step910 (i.e., the position of the shearer 125) and step 920 (i.e., the loadof the conveyor 300). The output of the mining system 100 can becalculated, for example, by determining how many tons of mined materialthe shearer 125 removes during a lateral movement along the mining face110, how many tons of mined material the conveyor 300 is moving towardsthe discharge portion 130 in a unit time (e.g., minutes, hours, etc.),etc. At step 930, the controller 400 analyzes the output of the miningsystem 100. In one embodiment, the controller 400 is configured oroperable to compare the output of the mining system to a predeterminedthreshold. The predetermined threshold is, for example, the maximumoutput of the mining system 100. As described above, the output of themining system 100 can be described as a percentage (%) of the maximumoutput of the mining system 100. Additionally or alternatively, thecontroller 400 can analyze the output of the mining system 100 using afunction and/or look-up table related to the output of the mining system100 (e.g., the present output of the mining system is an input to afunction or a look-up table and the function or look-up table producesnecessary control signals or parameters). Based on the analysis of theoutput of the mining system 100, the controller 400 is configured oroperable to control the speed of the shearer 125 (step 935). Forexample, the controller 400 can increase the speed of the motor 440driving the shearer 125 in order to increase the amount of minedmaterial removed from the mining face 110. The process 900 can beperformed continuously during the operation of the mining system 100 toconstantly adjust or modify the speed of the shearer 125 and theconveyor 300 in order to maximize the productivity of the mining system100. In some embodiments, the output of the mining system 100 is notdetermined and the position of the shearer 125 and the load of theconveyor 300 are used to directly control the speed of the shearer 125and the conveyor 300.

FIG. 9 illustrates a process 1000 for controlling the mining system 100.At step 1005, the controller 400 receives a first signal related to aposition of the shearer 125. The controller 400 is configured oroperable to determine or calculate a value for the position of theshearer 125, for example, as a percentage (%) of position along themining face 110 (step 1010). At step 1015, the controller 400 receives asecond signal related to a load of the conveyor 300. The controller 400is configured or operable to determine or calculate a value for the loadof the conveyor 300, for example, in units of tons per meter (step1020).

At step 1025, the controller 400 determines or calculates an output ofthe mining system 100 based on the characteristics determined in step1010 (i.e., the position of the shearer 125) and step 1020 (i.e., theload of the conveyor 300). The output of the mining system 100 can becalculated, for example, by determining how many tons of mined materialthe shearer 125 removes during a lateral movement along the mining face110, how many tons of mined material the conveyor 300 is moving towardsthe discharge portion 130 in a unit time (e.g., minutes, hours, etc.),etc. At step 1030, the controller 400 analyzes the output of the miningsystem 100. In one embodiment, the controller 400 is configured oroperable to compare the output of the mining system to a predeterminedthreshold. The predetermined threshold is, for example, the maximumoutput of the mining system 100. As described above, the output of themining system 100 can be described as a percentage (%) of the maximumoutput of the mining system 100. Additionally or alternatively, thecontroller 400 can analyze the output of the mining system 100 using afunction and/or look-up table related to the output of the mining system100 (e.g., the present output of the mining system is an input to afunction or a look-up table and the function or look-up table producesnecessary control signals or parameters). Based on the analysis of theoutput of the mining system 100, the controller 400 is configured oroperable to control the speed of the conveyor 300 (step 1035). Forexample, the controller 400 can increase the speed of the motor 445driving the conveyor 300 in order to increase the speed of the conveyor300 and the amount of mined material that is conveyed from the miningface 110. The process 1000 can be performed continuously during theoperation of the mining system 100 to constantly adjust or modify thespeed of the shearer 125 and the conveyor 300 in order to maximize theproductivity of the mining system 100. In some embodiments, the outputof the mining system 100 is not determined and the position of theshearer 125 and the load of the conveyor 300 are used to directlycontrol the speed of the shearer 125 and the conveyor 300.

In some embodiments, the controller 400 is also configured or operableto selectively enable or disable additional features or controls of themining system 100, such as bank push, snake loading, double snake,auto-drag, multiple advance, slewing the face, etc., based on theloading of the conveyor 300 and/or the output of the mining system 100.

For example, as the shearer 125 advances along the mining face 110, theconveyor 300 is advanced toward the mining face 110 to be ready for thenext pass of the shearer 125. The power associated with advancing theconveyor 300 in such a manner accounts for approximately 20% of theloading of the conveyor 300. As a result of the increased loading fromadvancing the conveyor 300, there is less loading available for thetransport of mined material along the conveyor 300. There are, however,natural reductions in the amount of loading on the conveyor 300 frommined material (see FIG. 5). For example, when the shearer 125 reachesthe end of the mining face, the shearer must change directions andperform other operations that allow the mined material on the conveyor300 to be conveyed away without being replaced as quickly, thus reducingthe loading on the conveyor 300 from mined material. As such, in orderto increase the output of the mining system 100, the controller 400 canslow or inhibit the advance of the conveyor (e.g., reduce the advancespeed of the conveyor, prevent the conveyor from advancing [i.e., reduceadvance speed to zero], etc.) during normal operation (e.g., not at anend of the mining face 110, between 10% and 90% of the length of themining face 110, between 20% and 80% of the mining face 110, etc.). As aresult, there is additional conveyor loading that is available that canbe used to increase the speed of the shearer 125 and/or speed of theconveyor 300. As the shearer 125 approaches an end of the mining face110 and the loading on the conveyor 300 from the mined material isreduced, the controller 400 can allow the conveyor 300 to advance towardthe mining face 110 (e.g., increase the advance speed of the conveyor).

Thus, the invention may generally provide, among other things, systemsand methods for controlling a speed a shearer and/or a conveyor in amining system based on an output of the mining system.

What is claimed is:
 1. A mining system comprising: a shearer; aconveyor; a first sensor operable to generate a first signal related toa position of the shearer; a second sensor operable to generate a secondsignal related to a load of the conveyor; a first drive mechanismcoupled to the shearer and operable to drive the shearer; and acontroller operable to receive the first signal from the first sensor,determine the position of the shearer based on the first signal, receivethe second signal from the second sensor, determine the load of theconveyor based on the second signal, determine an output of the miningsystem based on the position of the shearer and the load of theconveyor, and control a speed of the shearer based on the output of themining system.
 2. The mining system of claim 1, further comprising asecond drive mechanism coupled to the conveyor and operable to drive theconveyor and wherein the controller is further operable to control aspeed of the conveyor based on the output of the mining system.
 3. Themining system of claim 1, wherein the controller is further operable tocompare the output of the mining system to a predetermined threshold,and control the speed of the shearer based on the comparison of theoutput to the predetermined threshold.
 4. The mining system of claim 3,wherein the predetermined threshold is a maximum output of the miningsystem.
 5. The mining system of claim 1, wherein the first sensor is aposition sensor.
 6. The mining system of claim 1, wherein the secondsensor is a load sensor.
 7. The mining system of claim 1, wherein thefirst drive mechanism includes a motor.
 8. The mining system of claim 7,wherein the speed of the shearer is controlled by controlling a speed ofthe motor.
 9. A method of controlling an output of a mining system, themethod comprising: receiving, at a processor, a first signal associatedwith a position of a shearer; determining, using the processor, theposition of the shearer based on the first signal; receiving, at theprocessor, a second signal associated with a load of a conveyor;determining, using the processor, the load of the conveyor based on thesecond signal; determining, using the processor, the output of themining system based on the position of the shearer and the load of theconveyor; and controlling a speed of the shearer based on the output ofthe mining system.
 10. The method of claim 9, further comprisingcontrolling a speed of the conveyor based on the output of the miningsystem.
 11. The method of claim 9, further comprising comparing, usingthe processor, the output of the mining system to a predeterminedthreshold, and controlling the speed of the shearer based on thecomparison of the output to the predetermined threshold.
 12. The methodof claim 11, wherein the predetermined threshold is a maximum output ofthe mining system.
 13. The method of claim 9, wherein the first signalis generated by a position sensor.
 14. The method of claim 9, whereinthe second signal is generated by a load sensor.
 15. The method of claim9, wherein the load sensor is a tension sensor.
 16. The method of claim9, wherein the drive mechanism includes a variable speed motor.
 17. Amining system comprising: a shearer; a conveyor; a first sensor operableto generate a first signal related to the position of the shearer; asecond sensor operable to generate a second signal related to the loadof the conveyor; a first drive mechanism coupled to the conveyor andoperable to drive the conveyor; and a controller operable to receive thefirst signal from the first sensor, determine the position of theshearer based on the first signal, receive the second signal from thesecond sensor, determine the load of the conveyor based on the secondsignal, determine an output of the mining system based on the positionof the shearer and the load of the conveyor, and control a speed of theconveyor based on the output of the mining system.
 18. The mining systemof claim 17, further comprising a second drive mechanism coupled to theshearer and operable to drive the shearer, and wherein the controller isfurther operable to control a speed of the shearer based on the outputof the mining system.
 19. The mining system of claim 17, wherein thecontroller is further operable to compare the output of the miningsystem to a predetermined threshold and control the speed of theconveyor based on the comparison of the output to the predeterminedthreshold.
 20. The mining system of claim 19, wherein the predeterminedthreshold is a maximum output of the mining system.
 21. The miningsystem of claim 17, wherein the first sensor is a position sensor. 22.The mining system of claim 17, wherein the second sensor is a loadsensor.
 23. The mining system of claim 17, wherein the first drivemechanism includes a motor.
 24. The mining system of claim 23, whereinthe speed of the conveyor is controlled by controlling a speed of themotor.
 25. The mining system of claim 17, wherein the speed of theconveyor is a speed of conveyor advance toward a mining face.
 26. Amethod of controlling an output of a mining system, the methodcomprising: receiving, at a processor, a first signal associated with aposition of a shearer; determining, using the processor, the position ofthe shearer based on the first signal; receiving, at the processor, asecond signal associated with a load of a conveyor; determining, usingthe processor, the load of the conveyor based on the second signal;determining, using the processor, the output of the mining system basedon the position of the shearer and the load of the conveyor; andcontrolling a speed of the conveyor based on the output of the miningsystem.
 27. The method of claim 26, further comprising controlling aspeed of the shearer based on the output of the mining system.
 28. Themethod of claim 26, further comprising comparing, using the processor,the output of the mining system to a predetermined threshold, andcontrolling the speed of the conveyor based on the comparison of theoutput to the predetermined threshold.
 29. The method of claim 28,wherein the predetermined threshold is a maximum output of the miningsystem.
 30. The method of claim 26, wherein the first signal isgenerated by a position sensor.
 31. The method of claim 26, wherein thesecond signal is generated by a load sensor.
 32. The method of claim 26,wherein the load sensor is a tension sensor.
 33. The method of claim 32,wherein the drive mechanism is a variable speed motor.
 34. The method ofclaim 26, wherein the speed of the conveyor is a speed of conveyoradvance toward a mining face.
 35. A controller including a processor anda memory, the controller comprising executable instructions stored inthe memory to: determine a position of a shearer based on a first signalassociated with the position of the shearer; determine a load of aconveyor based on a second signal associated with the load of theconveyor; determine an output of a mining system based on the positionof the shearer and the load of the conveyor; and control at least one ofa speed of the shearer or a speed of the conveyor based on the output ofthe mining system.